1. Field of the Invention
The present invention relates generally to locomotive horn systems and other similar warning systems that ensure safety as a locomotive traverses a track and, in particular, to an operator warning system and method that improves the vigilance of the locomotive operator at various portions and positions on the track, such as at grade crossings and the like.
2. Description of Related Art
In order to operate a locomotive or train, an operator must interact with a train control system. These train control systems, in turn, bear directly on a locomotive operator's ability to control the locomotive horn. Further, the locomotive operator, typically referred to as an engineer, is required to sound the horn at an intersection of a road in the railroad track, and such intersections are known as grade crossings.
A locomotive operator is required to manage his or her train within the operating limits of the railroad, and must also strive to control the train, such that stresses within the train consist are limited, and the train effectively arrives at the destination within a scheduled timeframe. Accordingly, the responsibility of managing a train, coupled with the distractions within the locomotive cab, can lead to decreased vigilance in the repetitive task of sounding the locomotive horn at grade crossings. To add to this problem, an operator must also be aware of the crossings that do not require horn activation, and crossings that require horn activation only within certain hours of the day or direction of approach to the grade crossing.
According to the prior art, certain systems have been developed to increase crew vigilance with the introduction of crew alerter devices in the locomotive cab. These devices monitor operator actions, such as changes in brake settings, throttle settings or manual horn activation. In the event that no operator activity is detected within a particular interval of time, the alerter device attempts to gain the attention of the crew through a visual or audible indication. Further, if after a longer interval of time passes and no action has been taken by the crew, or if the system cannot determine whether the train is still in the control of the operator, the alerter device may time out and automatically apply the locomotive brakes.
Computer-based train control systems have taken crew vigilance to an even greater level by providing an onboard computer system that monitors train speeds, limits of authority and other restrictions and enforces these parameters. The integration of a track database with an onboard navigation system provides for the ability to warn an operator of potential speed or authority violations, thereby increasing vigilance. However, neither the crew alerter systems nor current train control systems provide vigilance for the express purpose of reminding the operator to sound the locomotive horn at a grade crossing. Therefore, there remains a need in the art to provide such a system.
Further prior art systems include methods that automatically sequence the locomotive horn according to regulations at required grade crossings. See, e.g., U.S. Pat. No. 6,609,049 to Kane et al. In particular, the system of this patent discusses the incorporation of an onboard database that includes grade crossings, a navigation system, a predictor that determines when to sound the horn according to the regulations and an interface to the locomotive horn. Although this system minimizes the potential for missed horn activations, it does not allow the operator to intervene or preempt the horn activation, as would be required during switching operations around grade crossings or other situations where the operator has greater situational awareness than the onboard computer. Therefore, there remains a need for a system that improves locomotive operator vigilance around grade crossings, but still provides the operational flexibility for an operator to perform his or her duty with respect to activation of the horn.